Granny Flat Approvals

granny flat approvals sydney

Granny Flat Approvals

There are two options for obtaining an approval for a granny flat aka secondary dwelling. They are:

Complying Development Certificate (CDC)

  • Must meet the requirements of Affordable Rental Housing SEPP 2009 – Secondary Dwellings.
  • Typically 14 Day approval with Certifier

Development Application (DA)

  • Some councils have their own set of controls for granny flats, which may or may not be more lenient than CDC controls.
  • Much lengthier approval, at least 1 month, could even take several months depending on which council.

Certificates required in designing your granny flat

Section 149 Part 2 Certificate – This is obtainable from council for about $80. Can take up to 10 days to get. It indicates things such as zoning, flooding, if the property is bush fire prone and many more, which are essential in knowing the suitability of your land for a granny flat and if there are any special requirements to that must be met.

Sewer Service Diagram (SSD) – This is obtainable from Sydney Water agent or council if it’s outside of Sydney for about $28. Online at for Sydney only. This will indicate if there are any Sydney Water sewer pipes on your land which are best to avoid building near.

Deposited Plan (DP) – This is obtainable from NSW information broker such as infotrack for about $25. This plan indicates if there are any easements on the property which restrict building.

Deposited Plan Image – This is obtainable from NSW information broker such as infotrack for about $25. Section 88B instrument sets out terms of easements or Profits à Prendre to be created or released and of restrictions on the use of land or positive covenants intended to be created pursuant to Section 88B Conveyancing Act 1919

Property Title – This is obtainable from NSW information broker such as infotrack for about $25. A title search is a current copy of the Certificate of Title which shows the current owner, the land description and any dealings associated.

Complying Development (CDC) requirements summarised

Lot Size (m2) Frontage (m) Maximum Site Cover Landscaped Area Floor Area (m2) (incl. house) Side Setback (m) Rear Setback (m)
450-600 12 50% 20% 330 0.9 3
600-900 12 50% 25% 380 0.9 3
900-1500 15 40% 35% 430 1.5 5
1500+ 18 30% 45% 430 2.5 10

(Do not rely on these entirely, refer to the Affordable Rental housing SEPP – 2009 Schedule 1 Development standards for secondary dwellings)

  • Granny flat floor area must not be more than 60 m² including external walls
  • Land must be at least 12 m wide (for lots up to 900 m²)
  • Land must be at least 450 m²
  • Battle-axe lots must be at least 12 m x 12 m
  • Max site coverage is 50% (including house, granny flat and sheds, but not awnings)
  • Front setback must be at least the average setback of the nearest two dwelling houses
  • Secondary setback must be at least 2 m for lots up to 600 m², and 3 m for lots up to 1,500 m²
  • Front setback from classified roads is a minimum of 9m
  • Rear setback must be at least 3 m for lots up to 900 m², and 5 m for lots up to 1,500 m²
  • Eaves and rainwater tanks may encroach on setbacks up to 450 mm from the boundary
  • Secondary dwellings on Corner lots must have a window of at least 1 m² in habitable room visible from the secondary road
  • At least 20% of the site must be landscaped for lots up to 600 m², 25% for lots up to 900 m² and 35% for lots up to 1,500 m²
  • At least 50% of landscaped area must be located behind the building line
  • Landscaped area must be at least 2.5 m wide
  • A private open space area of at least 24 m² must be provided to the granny flat that is directly accessible from the living area and at least 4 m wide
  • Fill must not exceed 1 m above natural ground level
  • All storm-water should be drained to either council’s system or an onsite disposal system, either gravity fed or charged
  • Granny flats must be setback from any protected trees by at least 3 m

Bushfire prone land

The section 149 certificate for your land will indicate if it is bushfire prone or not. Also, it is almost certain that a land is bushfire prone if the satellite image shows adjacent bush land.

In any case a BAL (bushfire attack level) report is required if the land is bushfire prone. These must be prepared by a qualified bushfire consultant, we can organise this if necessary.

The BAL rating can dictate types of building materials that may be required to resist bush fire attack. For example; metal fly screens, gutter leaf guard, thicker window glazing, are the usual requirements. These will increase the building costs, the higher the attack level the higher the cost increase.

It is important that a bushfire report is undertaken prior to commencing the design of a granny flat, in particular because if the BAL rating is above 29 a granny flat is not permissible.

It is best to consult with the bushfire consultant to get more info, in some cases they can even give an indication over the phone if the bushfire attack level is likely to exceed 29.

Flood prone land

The section 149 part 2 certificate will indicate if a land is flood affected or not. This can be serious or minor. To determine how serious this is, the section 149 part 5 certificate must be ordered from council (for approximately $150). This will give an indication of the type of flooding and the risk level.

If the land is ‘high risk’, affected by ‘overland flooding’ or it’s in a ‘flood path’, then the approval process will be more difficult, uncertain and may require the consultation of a flooding engineer.

If the land is simply ‘low-medium’ risk, than the CDC and DA process should be fairly simple, but a Flood Certificate will be required at an extra charge starting at around $800.

In any case, if the land is flood affected, you should contact council to verify that a granny flat is possible and what may be involved.

Council approval fees and private certification fees

All fees vary from council to council and you can contact council to get an exact quote.

Standard Fees:

DA/CC – Typically $500-$600 for the DA and $1,500 for the CC (includes inspections etc)

CDC – Typically $3,000 (depending on council)

Section 94 Contributions:

Section 94 contributions are the developer’s contributions to the local council. Each council has a budget for spending on things such as parks, libraries etc. This is what the section 94 contributions contribute to.

Some councils impose section 94 contributions for the development of granny flats. These can be thousands of dollars in some cases. Council should be contacted for a quote.

Note: Gosford council has cancelled section 94 contributions for granny flats.


A BASIX certificate is generated for the granny flat as part of the planning process, as is required for all new buildings.

The BASIX certificate provides the requirements for the building to be energy efficient. Typical requirements include (which are included in our turn-key price): Instantaneous-gas-hot-water system, Rainwater tank (usually 2,000L), Wall and Ceiling Insulation. Other requirements, such as glazing, we avoid as they cost much more.

Project Time Line for a turnkey granny flat

We do a typical turn-around of 3 months (pending weather and public holidays)

Site Survey Plan Preparation Approval (CDC) Build
1-2 weeks 1-2 weeks 2-3 weeks 2 months

Connections of Services


Up to 5 meters is included in our turn-key price. Electricity needs to be connected to the existing metering box. We install a sub-board inside the granny flat. If separate metering is required, this can be organised with your energy company at any time, we simply connect the power and separating metering can be done later.

Cold Water

Up to 5 meters is included in our turn-key price. Water needs to be connected to the nearest pipe work, a garden tap for example.


Up to 5 meters is included in our turnkey price. Sewer needs to be connected to the nearest suitable sewer pipe, but not to the mains pipe as this cannot be done by a normal plumber and will cost more.


We provision for the fitting of an LPG gas bottle with the instantaneous gas hot water unit which could last up to a year before requiring refilling. Arrangements can be made with gas supply companies to service, supply & refill the bottles. This is an inexpensive arrangement. If a gas connection to the existing supply at your property is required, we can also do this.

Building near sewer pipes

Sydney water owns Sydney’s sewer system. So Sydney Water’s rules must be followed for building near or on a Sydney Water sewer pipe.

In the Central Coast, Gosford and Wyong, the sewer system is owned by council. So the council’s rules must be followed for building near or on a sewer pipe.

The sewer service diagram needs to be obtained from the sewer system owner to determine if and where there are any sewer pipes on your property.

Zone of Influence

This is an area on either side of the sewer pipe, typically it is calculated as the depth+600mm. To gain a straight forward (and least costly) approval from the water authority, the building needs to be placed outside of this zone. Otherwise a much more stringent approval is required, and will likely involve costly building works to protect the sewer pipe work. These building works can include concrete encasing of the sewer pipe and deeper concrete pier depths to the granny flat slab.


We provide a standard home warranty insurance policy covering the granny flat structure for 6 years, as required by law.

Appliances come with 12 month warranty.

Everything else is provided with 2 years warranty.

Bank loans

If you wish to obtain a bank loan for the money to construct your granny flat, we can assist you with this by providing the documents required such as the fixed price granny flat building quote, granny flat plans and finishes schedule and a fixed price building contract or design and construct contract.

The best way to start this process is to approach your lender with our free-quote that we provide for you after your free-consultation and site inspection. With this your lender should have no problem preparing your pre-approval.

Once your plans are prepared and approvals are granted, we then provide you with a fixed-price building contract that they can take to their bank to start on the progress payment schedule